Controlled Framework Shutdown and Timing

[SamGinrich]

TVision over NCurses nicely remotes mouse interactions with ssh.

In a regular linear control flow, e.g. of a configuration script, one might introduce several transient Dialog Views to enter complex parameters.

1.) It turns out, that a TApplication creates screen management objects, which do not end with the TApplication's lifecycle,
such that the contsole screen is not freed and subsequent console output is not readable.

A working solution is to call TScreen::suspend() after the TApplication object has been destroyed.

	TMyApp myApp();

	bool res = false;
	try
	{
		myApp.run();
		res = mxApp.getOK();
	}
	catch (const std::exception& x)
	{
		...
	}
	std::this_thread::sleep_for(std::chrono::milliseconds(50));
	TScreen::suspend();
	std::this_thread::sleep_for(std::chrono::milliseconds(50));
	...

Question: Is this a valid approach or are there further objects to be released, for a proper cleanup,
or same might be reached in the TApplication's destructor?

2.) The code fragment above worked without delay frame around TScreen::suspend() in the Debug version.
Switching to Release build, though, the SSH-client got confused,
the protocol entered some raw mode, began displaying mouse moves and key strokes were no more accepted.

Question: Are there TVision- or NCurses-internal states to be set to reach controlled behaviour without delays,
or can one clearly conclude, that the problem is on the network/ssh side?

[magiblot]

Hi, @SamGinrich!

At first glance, you are doing nothing wrong. TScreen::suspend() (or myApp.suspend()) should restore the console state completely.

I tried the following sample program, but I was unable to replicate the situation you described (inability to type more input), even if using a SSH connection with a noticeable delay. Therefore, I ask you two things:

• Could you please confirm whether you can still reproduce the issue with the following program?
• Which terminal emulator are you using? What happens if you try other terminal emulators?

Cheers.

#define Uses_TApplication
#define Uses_TDeskTop
#define Uses_TBackground
#define Uses_TInputLine
#define Uses_TDialog
#define Uses_TScreen
#define Uses_TButton

#include <tvision/tv.h>
#include <iostream>
#include <string>

class TMyInputDialog : public TDialog
{
public:
    TInputLine *input;

    TMyInputDialog(TStringView title) :
        TWindowInit(TWindow::initFrame),
        TDialog(TRect(10, 5, 70, 15), title)
    {
        options |= ofCentered;

        TRect r;

        r = TRect(20, 6, 30, 8);
        insert(new TButton(r, "OK", cmOK, bfDefault));

        r = TRect(3, 3, 53, 4);
        input = new TInputLine(r, 255);
        insert(input);
    }
};

class TMyApp : public TApplication
{
public:
    TMyApp() :
        TProgInit(
            /* initStatusLine */ nullptr,
            /* initMenuBar*/ nullptr,
            initDeskTop
        )
    {
    }

    static TDeskTop *initDeskTop(TRect r)
    {
        TDeskTop *deskTop = new TDeskTop(r);
        return deskTop;
    }

    std::string getInput(TStringView title)
    {
        std::string userInput;

        TMyInputDialog *dlg = new TMyInputDialog(title);
        if (deskTop->execView(dlg) == cmOK)
            userInput = dlg->input->data;
        destroy(dlg);

        return userInput;
    }
};

int main()
{
    TMyApp app;
    std::string firstInput = app.getInput("Enter Input");

    app.suspend();

    std::cout << "First input (from Turbo Vision): " << firstInput << std::endl;

    std::string secondInput;
    std::cout << "Enter another input: ";
    std::getline(std::cin, secondInput);

    std::cout << "Second input: " << secondInput << std::endl;

    app.shutDown();
}